This invention relates to so-called pavers or finishers, of the type adapted to receive aggregate, such as a mixture of crushed rock and asphalt, and then to spread the aggregate as a smooth layer over a surface being paved. In the usual instance, the aggregate is supplied to the paver from a dump truck which is positioned in front of the paver and which, with raising of the dump body in the truck, dumps aggregate into a receiving hopper which is provided in the paver.
With larger units having a receiving hopper of appreciable size, problems have been experienced in moving aggregate deposited within the hopper whereby such may be caused to cascade downwardly from the hopper into the region being paved and in advance of any screed in the paver, which is the instrumentality in the paver that smooths and spreads the material on the surface being paved. If the hopper is made tiltable to cause material to flow by gravity downwardly in advance of the screed, problems arise in connection with the dump truck which supplies the paver material. Specifically, on raising of the hopper, the hopper tends to move against the dump body of the truck which limits its upward movement and which requires that the truck move away from the paver during such tilting movement. If the dump truck has not fully dumped its load, it must then back up against the paver to complete depositing its load, this being preceded by lowering of the hopper to permit such movement. The operation described is time consuming. To obviate the problem, drag chains and the like may be included which extend along the base of the hopper for moving material rearwardly and toward the screed region. However, a drag chain has a return run which of necessity travels under the hopper. A drag chain is difficult to clean, and the return run described tends to drag material with it under the base of the hopper.
In U.S. Pat. No. 4,718,790, there is disclosed a paver with one or more rotating discs which form the floor of the hopper in the paver. With rotation of the discs, aggregate within the hopper is caused to be moved rearwardly to a region where the material cascades downwardly in advance of the screed of the paver. The construction disclosed in the patent obviates the problems above generally discussed, in enabling control of material flow without requiring that the hopper be tilted completely to achieve it, and without the problems encountered by drag chains or similar conveyor systems.
Disclosed herein is a form of paver constituting an improvement in the class of paver generally disclosed in the above-identified prior issued patent. More specifically, the invention resides in an improved form of disc or discs to be incorporated with such a paver, which promotes aggregate mixing and distribution during the paving process. A further and related feature of the invention is the provision of a paver incorporating one or more discs for producing aggregate movement which may have a lighter weight than when discs of comparable overall size are used as disclosed in the prior patent.
In a specific and preferred embodiment of the invention, a disc is provided which has arms extending outwardly from a central hub which mounts the arms with the outer extremities or ends of the arms forming the perimeter of the disc. The arms have voids or spaces therebetween separating one arm from another, which material may fall into during operation of the disc to produce mixing and churning and a more aggressive feed of the material which overlies the disc. Material working to the arm extremities is discharged in advance of the screed in the paver which does the leveling operation. A detachable mounting may be provided for connecting the arms to the hub, to enable replacement of one or more arms for repair or maintenance purposes.